Safety operation by buffer



Aug. 30, 1932. H. D. JAMES 1,874,754

SAFETY OPERATION BY BUFFER Filed April .18 1950 2 SheetsSheet 1 INVENTOR Henry Pjames.

AT'TORNEY Aug. 30, 1932. H. D. JAMES v 7 OPERATION BY BUFFER Filed April 18. 1930 2 Sheets-Sheet 2 I INVENTOR Henn ZZ J'ames. Y

A ATITORNEY I Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE HENRY 1). JAMES, or EDGEWOOD, PENNSY VANIA, ssIGNoE T WESTINGHOUSE ELEC- TRIO & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA SAEE'rY OPERATION EY BUFFER Application filed April is,

My invention pertains to a safety device for checking the speed of an elevator car and more specifically to a combination safe ty-bufier in which theengagement of the safety-breaking device carried by the car to aid the buffer in checking the car speed.

It is common, in elevator practice, to provide a buffer in the pit at the bottom of the 10, elevator shaft to gradually absorb the kinetic energy of the moving car and bring it tofa impart to it a velocity equal to the velocity of the car. The shock of the impact sets'up vibrations in the car which are detrimental to the equipment and cause discomfort to the passengers. Furthermore, bufi'ers suit able for checking the speed of modern highspeed elevators are difficult to design and install. i

It is, accordingly, an object of m invention to provide a buffer-safety com ination which will eliminate the diificultiesand dis advantages attending the conventional buffer installations. g

It is an object of my invention to provide means carried by an elevator car for engag 'ing the buffer to gradually absorb the inertia of the moving portion of the buffer. 35 It is also an object of myinvention to pro vide a braking device and a buffer-engaging means carried by the car to gradually absorb the inertia of the moving portion of the buffer and simultaneously apply the braking device.

It is a further object of my invention to provide a braking device carried by the elevator car which will be'automa-tically applied by the engagement of the car and'the buffer with a force commensurate with the velocity and loading of the car.

In accordance with my invention, the plunger of the buffer is provided with a head of wedge-shape, and the car is provided with a pair of aws having angularly buffer by the car causes the application of a 1930.; Serial No. 445,319.

disposed surfaces suitable for engagement withthe head of. thebuifer. A brakingdevice is carried :by the car and is associated evident from the following detailed description, taken in conjunction with the companyingdrawings, in which Fig. 1 is a view partially in side'elevation and partially in section, showing an elevator car and a buffer arranged in accordance with my invention.

Fig. 2 is a sectional side view of the car safety-braking device, taken on the sect-ion lines IIII of Fig. 3, and 1 Fig.3 is a sectional plan view of the car safety-braking device taken on section lines IIITIII of Fig. 2. 7

Referring to the drawings, the apparatus shown in Fig. 1; comprises an elevator car G operating between guide rails 1 and 2 in the usual manner. The hoist equipment and control apparatus has been omitted since it may comprise any conventional elevator installation and would complicate the disclosure if shown. 7 As shown in Fig. 1, the plunger 3 of a buffer B is provided with a head 4 of wedgeshape which enters between a pair of en aging aws 5 and 6 carried by the'oar. eans is provided within the bufler to prevent rotation of the piston and maintain the head 4 in its proper relative position. It will be apparent that the entrance of the head will. force apart the jaws 5 and 6 and their associated shafts 7 and 8. The motion of the shafts 7 and 8, when forced apart by the entrance. of the head 4, causes the application of the car safety device to grip the rails, in a manner more fully set forth with reference to Figs. 2 and 8. .7

' If the car engages'the buffer at a very high velocity, thebufier head 4 will be forced through between the jaws 5 and 6 and will engage the impactplate '14 carried by the car.

Engagement-with the plate 14 will-cause the Y movable portion ofthe buffer to travel with aveloclty equal to thatof thecar, but, before The inner extremities of shafts 7 and 8 carry jaws 5 and 6, respectively, for receiving the head 4: of the buffer plunger, as previously set forth. To prevent rotation of the jaws 5 and G, a guide 32 is provided. The outer extremities of the shafts carry wedge members'34c which'are supported with their apices directed outwardly. The apex of each wedge is received between a pair of rollers 36 and 37, shown more clearly in Fig; 3, and the rollers are journaled in the ends of levers 38 and 39 mounted upon the pivot members 41. The outer extremities of levers 38 and 39 are provided with suitable braking surfaces 43'a'nd 44 for engaging the guide rails 1 and 2 to stop the car. j I v V The movable parts of the braking device carried by the car constitute a brake actuator which diverts a portion of theforce of engagement of the car on'the buffer to apply the brake. V

Springs 43 and 49 are provided to normally hold the roller-supporting ends of the levers 38 and 39 together and the braking ends of the levers apart and disengaged from the rail. Springs 33Vare provided to retrieve the shafts 7 and 8 to their inoperative positions. My invention is more readily described, however, when considered in connection with an assumed operation thereof.

Assuming that the car descends and strikes the buffer, and the head 4 enters between the jaws 5 and 6, the entrance of the head 4 between the jaws 5 and 6 will force them'apart, and they will',in turn,/force the shafts 5 and 6 outwardly, thereby forcing the wedges'34 v between. the two pairs of rollers 36" and 37.

When the rollers 36 and 37 are forced apart, the levers 38 and 39 will be rocked about their pivots 41, in a manner similar to a pair. vof scissors,thereb-y urging the braking surfaces 43a'nd t'together to squeeze'the webs of the guide rails and check the speed of the car. It'Will be apparent that the impact of the car striking the buffer will be very slight since it is absorbed gradually by the slidable engagement of the head with the jaws and the springs'33. I 1

The force withxwhich the car safety-braking device is applied will be commensurate with theforceof engagement of the car with thebufier which is proportional to the velocity of the car and-the load carried thereby. In addition to the braking effort applied by the car-braking device, the bufier will also be ing device carried thereby, a buffer mounted on the bottom of thehatchway for engaging the car to reduce its speed when it overruns a terminal, and brake-actuating vmeans carried by-the car for diverting a port1on of the 'force of engagement of the car with the buifer to apply said braking device, with'a force proportional to the velocity'and loading of thecar. I p

.2. The combination with an elevator car operating between guide rails, and a buffer mount-ed On the bottom of the hatchWay between said rails and below the normal lower limit oftravel of said car, ofa braking device carried by the car comprising rail-gripping members and actuating means therefor engageable by the buffer to actuate the braking device, and absorb the inertia impact energy." 3. In combination with an elevator car, a bufier mountedin the path of movement of said car below the normal lower limit of travel thereoffa head of wedge shape on the plunger of said bufier, a braking device carried by the car, and actuating means for applying said braking device to stop the car comprising cooperating surfaces operative to receive said buffer headtherebetween to divert a portion of the force of engagement of the car with the bufi'er. for the purpose of applying the braking device, and absorbing the inertia impact energy.

4. In combination, an elevator car movable vertically 1n a shaft, a buffer mounted on the bottom of saidshaft for engagement with the car, a head of wedge shape carried by the'plunger of said buffer, a braking de vice carried the car comprising means 'for gripping the rails to stop the car, and actu-' ating means. for applying said braking, device comprising cooperative fiat surfaces 010- erative to receive said buffer head therebetween, and means for transmitting the force so diverted'to move the said gripping means into operative engagement with the rails, when the carengages the bufig'er. 'In testimony whereof, I have hereunto sub scribed my name this 11th day of April, 1930.

. I HENRY 1); JAMES. 

